Effects Of Human Umbilical Cord Mesenchymal Stem Cells Intramuscular Injection On The Cardiac Function And Myocardial Ultrastructure In Adriamycin-induced Dilated Cardiomyopathy Rats

Objective To explore the effects of intramuscularly grafted human umbilical cord mesenchymal stem cells on the cardiac function and myocardial ultrastructure in rats with adriamycin-induced dilated cardiomyopathy (DCM).Methods160rats were randomly divided into control group (n=20) and dilated cardiomyopathy group (to abbreviate:DCM group, n=140), rats in DCM group were administered adriamycin (2.0mg/kg) intraperitoneally once a week for8weeks to establish DCM model. The successfully established DCM rats were randomly divided into model control group (to abbreviate:model group), the supernatant group of human umbilical cord mesenchymal stem cells (hUCMSC)(to abbreviate:supernatant group), the low-dose group of hUCMSC (to abbreviate:low-dose group), the medial-dose group of hUCMSC (to abbreviate:medial-dose group), the high-dose group of hUCMSC (to abbreviate:high-dose group). Echocardiography was performed to evaluate the cardiac function, plasma brain natriuretic peptide (BNP) level and serum cardiac troponin I (cTNI) level were detected by enzyme-linked immunosorbent assay kit (ELISA), light microscope and transmission electron microscopy (TEM) were performed to observe the ultrastructure of myocardium.Results After the administration of hUCMSC, left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were significantly increased in low-dose and medial-dose hUCMSC group compared to those before the injection (P<0.01), as well as those of model group and supernatant group (P<0.01).The concentration of plasma BNP level and serum cTNI level were significantly decreased compared to those before the injection (P<0.01), as well as those of model group and supernatant group (P<0.01,0.05). The results of HE staining showed that cardiomyocytes orderly arranged, edema decreased and cell nucleus homogeneously stained in low-dose and medial-dose group. The outcomes of TEM revealed that the ultrastructure of cardiomyocytes were improved in low-dose and medial-dose group compared to that of model group, such as cardiomyocyte sarcolemma remained intact, the swelling of mitochondria ameliorated and the cristae of mitochondria remained clear.Conclusion Intramuscularly grafted hUCMSC could significantly increase LVEF and LVFS, decrease plasma BNP level and serum cTNI level, attenuate the myocardial pathological damage and improve myocardial ultrastructure in rats with adriamycin-induced dilated cardiomyopathy.